Plug valve



July 5, 1938. s vJ. NORDSTROM PLUG VALVE Filed May 27, 1955 ATTORNEY.

` PatentedlJuly 5, 1938v UNITED STATES- PATENT oFFicE PLUG VALVE Tapered the control ing gas and sive than other types commercial pose limitations therefore pressure generally recognized Sven J. Nordstrom,

Merco Nordstrom Valve Company,

Piedmont, Calif., assignor to Pittsburgh,

Pa., 'a corporation of Delaware Application May 27, 1935, Serial No. 23,537 4 Claims. (Cl.25193) plug valves are used extensively for of Water, compressed air, illuminatthe like because they are less expenof valves, but lubricated have 'found only a limited application requirementsof these industries imupon the cost of valves, and lubricated plug valves while as greatly superior to nonlubricated plug valves, have not-been extensively used in those installations where cost is an irnportant consideration.

It is an object of my invention to provide a pressure lubricated plug valve structure which will be relatively inexpensive to manufacture and will therefore be commercially applicable to a wide field of use. A

It is a further object of my invention to provide a plug valve structure in which'lubricant under pressure may be used for jacking, sealing, and

lubricating the valve and in which provision is made for continuously maintaining a substantially constant resilient seating force on the plug without the necessity of frequent readjustment of the valve or replacement of parts thereof.

It is a further object to provide a lubricated or nonlubricat ed valve in which a fibrous packing material is utilized'to prevent leakage of lubricant or of line iiuid to the exterior of the valve, and in which a spring is provided to take up any shrinkage or permanent set of vthe packing so as to maintain the plug constant pressure.

Itisai seated at a substantially urther which a lubricant chamber is provided adjacent the smaller end oi the plug to jack the plug from its seat,

ployed to prevent and in which the packing enileakage from said chamber is additionally compressed upon jacking of the plug from its seat, thereby sistance to providing additional rethe escape of lubricant or line iiuid between the packing and the plug.

A further object sive lubricant lift type is the provision of an inexpenn of plug valve whereby the packing utilized to resiliently maintain the plug seated is consantly sealed and lubricated.

A further object of the' invention is to provide means whereby the resilient holding force upon the plug position than will be greater when the plug is in closed when itis in open position.

These and other objects of the invention will be apparent from a consideration of the following specification taken in 'connection with the annexed dr awing in which:

object to provide a valve in the rigid washer i6.

shown in Figure 1;

Figure 3 is a sectional view of a further modiication. and y Figure 4 is a bottom elevation of a portion of Figure 3'.

Referring to the drawing, the numeral i designates generally the casing or body of my improved valve having a passageway 2 therethrough for flow of. fluid, and a tapered bore 3 forming a valve seat extending transversely thereof. A tapered plug t is seated in the valve seat 3 and has a port 5 extending therethrough adapted to register with the passageway 2 in the open position of the valve. The plug has an extension 6 projecting from the casing Iand which is .noncircular at its end to receive a wrench (not shown) for operating the valve. A lateral extension 'i is formed preferably integral with the extension t, and a dependwith the lugs 9 and 9 formed on the body to limit angular rotation of the plug to for full open and full closed positions.

The lower portion of the body is formed with an extension l0 having a bottom wall which is bored as indicated at ii, anda cylindrical extension I2 on the plug t, preferably formed integral therewith, extends with a loose fit through the hole ii. The 'extension it) is counterbored at I3 and provides a shoulderi3 at the bottom -of the counterbore on which are seated a plurality of fibrous packing washers it, shown as three in number, but which may be any desired number, located in the counterbore i3. The washers it may be made of asbestos composition, leather, or any other suitable fibrous material. An anti-friction Washer i5 made of phosphor-bronze or any other suitable material is located ontop of the packing washers lli, and a rigid washer i6 is superposed upon the anti-friction washer i5. The end of cy lindrical extension i2 of the plug is threaded as indicated at il and receives a castellated nut I8 which is held in place by a pin or key i9 passing through one of the slots 2i! in the nut i8. A spring 2i is interposed between the nut i8 and Preferably, this spring is in the form of a split steel lock washer and forms a'relatively sti spring with sufficient amplitude of action to take up any shrinkage or compression of the gaskets lli without materially altering the seating pressure of the plug on its seat. k

From the description so far pursued, it will be apparent that the Atapered plug 4 is held in its seat by the combined resiliency of the spring I1 and fibrous packing washers I4, and the resilient seating pressure of the plug against its seat can be adjusted within desiredl limits by adjustment of the nut I8 to compress or expand the spring 2 I.

The extension 6 of the plug is counterbored and threaded as indicated at 25 to provide a lubricant reservoir, and receives lubricant compressing screw 26 therein. The lubricant reservoir 25 connects at its bottom with a lateral passage 2'I formed in the plug, the passage 2`| having a widened mouth 28 which receives a ball 29, and which is adapted to seat on the chamfered shoulder 30 formed between the bores `2`I and 28. A circumferential groove 3| is formed in the plug at its top and connects with the mouth 28 of the lateral groove, and the casing may have a directly opposite circumferential groove 32 formed in the seat which overlaps the groove 3| to enable uniform lapping of the plug in its seat. A lubricant 'chamber 35 is formed# in the casing adjacent the bottom of the plug, and diametrically opposite longitudinal grooves 33 and 34 are formed in the surface of the plug.

and connect the circumferential groove 3| with the lubricant chamber 35. Lubricant under pressure from chamber 35 passes' through the clear-- ance between the bore I I and extension I2 to seal the union of the packing washers I4 and shoulder I3. As the packing washers I4 do not rotate 'relative to the shoulder I3 a permanent seal is thereby accomplished.

The operation of the valve now will bedescribed. The valve is lubricated by inserting a stick `of lubricant in the reservoir 25, and turning of the screw 26 into the bore 25 forces the lubricant before it through the lateral passage 21, past the ball check valve 29, into the circumferential grooves 3| and 32, and from thence the 4lubricant is conducted through the longitudinal grooves 33 and 34 to the lubricant chamber 35 at the bottom of the valve. The brous packing material I4, which preferably is in the form of washers, is compressed against the extension I2 of the valve and the retaining shoulder I3 by the resilient spring 2'I. With this construction suiicient lubricant pressure can be developed vin the chamber 35 at the bottom of the plug to jack or lift the plug slightly from its seat, thereby providing a small space between the surface of the plug and the seat into which lubricant is extruded from the chamber 35, circumferential grooves 3| and '32, 'and the longitudinal grooves 33 and 34 to seal and lubricate the valve seating surfaces.

The spring 2| in connection with the brous packing washers I4 provides a resilient seating pressure on the plug which permits suiicient movement of the plug to effect this longitudinal jacking by lubricant pressure. The use of brous washers I4 avoids V` the necessity forvaccurately grinding and lapping the retaining shoulder I3 and the cylindrical surface of the extension I2, and the lubricant which passes through the clearance between the bore II and extension I2 seals the small irregularities betweenl the packing I4 and shoulder I3', and also between the packing and plug extension I2. Were lubricant allowed to escape at these points it would interfere or even prevent the development ot suiicient lubricant pressure in chamber 35 to jack the plug. Any tendency for the packing washers I4 to shrink due to repeated compression or aging of the material therein is taken up by llike that shown in Figure 1 the spring 2| which has a relatively greater amplitude so that the resilient seating force on the plug remains substantially constant over long periods of time. Also, any clearance formed by such shrinkage of the surface of packing I4 against shoulder I3' is automatically sealed by lubricant. As the packing does not rotate, the lubricant serves merely as a seal. Further, the jacking of the plug from its seat compresses the spring 2| and washers I4 and thereby urges tlie Washers I4 more tightly against the shoulder I3' and cylindrical extension I2. The arrangement of longitudinal grooves 33 and 34 and of the stop lugs 8 and 9 is such that when the plug is turned clockwise as Vshown in Figure 2 for closing the valve, the grooves are not exposed to the line uid in the passageway 2. It will be understood that any desired system of lubrication for lubricating and jacking the plug l ceives the threaded end 42 of a cylindrical ex- A tension 40 having a castellated head 43 integral therewith. In this modication there is an extension 44 on the valve casing I', which casing is otherwise similar to valve casing I, having a transverse bore 45 therethrough, and the eX- tension 4I) passes through a bore 46 formed in the casing, a shoulder 4'I being formed between the bore 46 and a counterbore 48 through the eX- tension. A plurality of packing washers I4 are received in the counterbore 48, and the antifriction washer I5 and rigid washer I6 are superposed thereon. A split locking washer 2| abuts rigid Washer I6 and the castellated head 43, and it will be seen that in this vconstruction the spring 2| and brous packing washers I4 resiliently maintain the plug on itsv seat. A key 49 passes through the bore 45 in the extension 44 and the-.slots 5I` in the castellated head 43 to maintain the extension 40 in nonrotatable position with relation to the casing.

From the description so far pursued, it will be seen that when the valve plug 4' is rotated to closed position, the pitch of the threads 'on the extension 40 and in the bore 4I in the valve plug will tend to draw the tapered plug into its seat, thereby compressing the spring 2| and resilient washers I4 to insureA a tight resilient seating of the plug in Vits seat. Upon turning the valve counterclockwise to open position the threaded engagement of extension 40 in the bore 4I will tend to raise the plug 4 or relieve the resilient seating pressure of the spring 2| and washer I4 on the plug thereby making the valve easier to turn. The plug is adapted to be jacked from its seat by lubricant pressure, and this jacking can -adjacent the bottom `of plug 4. The clearance between bore 46 and extension 4U allows lubricant to pass to and seal the space between shoulder 41 and the packing I4 in the same manner as previ- Ously described in connectionv with the modification shown in Figures 1 and 2. The system for introducing lubricant to this chamber is exactly and the description thereof need not be repeated.

The invention may be embodied in other specinc forms without departing from the spirit or essential characteristics thereof. The present embodiment therefore is to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather `than by `the foregoing description, and all ehanges which :come within the meaning and range of equivalency of the claims are therefore intended to be yembraced therein.

What is claimed and desired `to lbe secured by United States 'Letters Patent iszil. In a `plug valve, 'the `combination @of la body, a tapered valve plug disposed therein, passageways in lthe 'lbody and Aplug for :controlling the ilow of duid, la .nonrotating extension `at 'ithe :smaller end of the `plug forming :a threaded `connection therewith, packing .surrounding the 'extension and seated against -the body. :a :spring superposed upon 'the packing, and :means on said extension cooperating `with the spring to `draw 'the `,plug :to- Ward its seat.

.2. In a `plug valve, the combination of :a tbody, a tapered valve plug disposed therein, passagekWays in `the body and `plug for ycontrolling the new of Liluid, Ypeeking seated Iagainst the Vbody adjacent the smaller end of `the plug, a 'spring superposeci upon vthe packing,- `a :nonrotating extension at the .smaller end of the jplug cooperating with `the spring to draw the plug `toward its seat, and means for moving the plug away from :its vseat by lubricant under pressure.

3, In a plug valve, the combination oi a. body.

;posed `upon `the .rigid washer, means for retaining said extension .against rotation, means Lon said :extension `cooperating with the `spring to draw the jplug toward its seat, `and `means for supplying llubricant `under pressure to said chamber for mov- `ing the jplug away from its iseat.

4. In ,a plug valve, the 'combination oi -a body 4with `a tapered valve plug disposed therein. passagewaysin 4the body and plug 4for controlling the 'ow of fluid, an extension at the `smaller end of the plug, said Vplug and extension vbeing .relatively axially movable to alimited extent upon rotation of `the plug, `paelring surrounding the extension :and seated against the body, `a, `spring superposed upon the packing, .means on vthe extension cooperating `with the spring whereby said spring draws the iplug towards .its seat. means ifor ysupplying .lubricant under pressure for moving `the `.plug

away `from its seat, and means for retaining said extension against rotation `relative to* the casing. 30

ASVEN J. 

